I've had a look around and AFAICT, the Microsoft.Win32.RegistryKey class
doesn't have any members that write the registry to a reg file. So, as I see
it, the options are:

1. Use Microsoft.Win32.RegistryKey to parse each value and write each to a
reg file manually. This is a bit of a pain as I have to write all the code
to keep the syntax of the resultant reg file correct.
2. Shell out and use regedit /e to export the file. Not ideal because when I
do this, I believe that a separate thread is used, so my app carries on
working whilst the registry is still being exported (noticeable for large
exports). OK, I could monitor all this, but again, this seems like really
hard work for such a simple job!

3. Use "advapi32.dll". This is my preferred option (assuming I'm right about
point 1). However, I'm getting errors when running the code:

[DllImport("advapi32.dll", EntryPoint="RegSaveKey")]
public static extern int RegSaveKey(IntPtr hKey, string lpFile, int
lpSecurityAttributes);
IntPtr hKey;
IntPtr hHkcu = new IntPtr((int)RegistryHive.CurrentUser);
int ret = Win32.RegOpenKey(hHkcu, registrykey, out hKey);
if(ret == Win32.SUCCESS)
{
Console.WriteLine("Return code: " + RegSaveKey(hHkcu, @"C:\regbackup.reg",
0).ToString());
}

This compiles fine, and it appears to be trying to do what it's supposed to
do. E.g. if I ensure that the file already exists, I get return code (from
RegOpenKey) 183, which is what the documentation to RegSaveKey says I should
get (file already exists, roughly). So, if I then make sure that the file
doesn't exist, instead of getting return code 0, I get 1314, which seems to
be a permission problem? However, I am an administrator.

If I do the same from the command prompt using regedit, it exports fine.

Any idea?

Cheers
Mark

Mark,

The MSDN docs say you need the SE_BACKUP_NAME privilege enabled. Even
if you're an admin you may have to enable this explicitly with
AdjustTokenPrivileges and related functions first.



Mattias

Indeed it does - I didn't spot that. However, it still doesn't work:

1. The SE_BACKUP_NAME privilege maps to SeBackupPrivilege, which is
displayed as "Backup files and directories" in the gp editor. This user
rights has two members: Administrators and Backup Operators. I am already a
member of the former, so I should already have this privilege.

2. I did write some code to add in the privelege anyway, using
OpenProcessToken, LookupPrivilegeValue and  AdjustTokenPrivileges. The extra
code ran fine without errors, but I still get error 1314, when running
RegSaveKey.

Any further ideas?

Cheers
Mark

Show quoteHide quote

Show quote Hide quote After much messing around with permissions, RegOpenKeyEx (KEY_ALL_ACCESS),
NTFS premissions, you name it, I tried it... I was still getting error 1314.
I guess that it's just not possible to use RegSaveKey from a managed
environment? So... I went for the clunky option 2 (shell out to
regedit.exe)! Works fine.

Show quoteHide quote

Show quote Hide quote Update:

Thought you might want to know - I found where I was going wrong in code.
Nothing to do with RegSaveKey or any of the other dllimports. Simple error
in the TOKEN_PRIVILEGES struct. I had:

[StructLayout(LayoutKind.Sequential)]
public struct TOKEN_PRIVILEGES
{
public LUID Luid;
public int Attributes;
public int PrivilegeCount;
}

It should have been:

[StructLayout(LayoutKind.Sequential)]
public struct TOKEN_PRIVILEGES
{
public int PrivilegeCount;
public LUID Luid;
public int Attributes;
}

D'oh! [Slap forehead]

[snip]

Error while executing my app on a target/client machine?
sorting columns of DataSet
String conversion from an Object in VB.NET
installing .net framework on XP Pro
Silent install of .Net Framework 1.1
Determining which Drive is the CD-ROM drive
KISS Tutorials
Unable to reuse remoting port
Change of .NET framework website
Uninstalling Microsoft .NET Framework 1.1 Sercice Pack 1